Markdown Syntax Highlighting not showing in preview

[ffrixslee]

Issue Type: Bug

Previously it was working.
Now the fenced code blocks are not showing any syntax highlights in the VSCode Markdown preview.
The problem is I would like to preview the markdown file in its syntax highlight before pushing commits to Github. As can be seen, the syntax highlights are shown in Github.
Code example:

awesome = ["Papuchon", "curry", ":)"]   
also = ["Quake", "The Simons"]   
allAwesome = [awesome, also]

Extension version: 0.1.1
VS Code version: Code 1.49.0 (e790b931385d72cf5669fcefc51cdf65990efa5d, 2020-09-10T13:22:08.892Z)
OS version: Windows_NT x64 10.0.18363

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-6560U CPU @ 2.20GHz (4 x 2208)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on oop_rasterization: disabled_off opengl: enabled_on protected_video_decode: unavailable_off rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	15.59GB (7.06GB free)
Process Argv	--crash-reporter-id 524d91ad-a30b-412d-9eb0-27ef7d9f818a
Screen Reader	no
VM	0%

[davidolrik]

I also see this problem, or a variant of it.

If I have this extension enabled, all code blocks render as plain text - This includes other extensions like Markdown Preview Mermaid.

Version: 1.52.1
Commit: ea3859d4ba2f3e577a159bc91e3074c5d85c0523
Date: 2020-12-16T16:30:02.420Z (6 days ago)
Electron: 9.3.5
Chrome: 83.0.4103.122
Node.js: 12.14.1
V8: 8.3.110.13-electron.0
OS: Darwin x64 20.2.0